1. Field of Invention
The present invention relates to a more environmentally affirmative system structure for treating household sewages. Aerobic and anaerobic bacteria living in the local soil decompose hydrocarbons, nitro-compounds, and phosphorous compounds in a household sewage. Worms living in the soil digest these decomposed harmful material. Grass and flowers covering the reaction bath along with microorganisms and worms biologically decompose these harmful materials eventually to be used as fertilizer.
2. Description of the Prior Art
Microorganisms and bacteria have been widely used for sewer treatment. Typical treatment scheme includes use of primary settlers, bio filters, aeration tanks and secondary settlers. U.S. Pat. No. 6,217,759 to Kolesnikov, et al. teaches of a device for biochemical sewage treatment, containing biocoagulators to provide oxidation of the sewage nitrogen compounds utilizing bio stimulating effect of a He—Ne laser (HNL).
U.S. Pat. No. 6,200,472 to Donald, et al. illustrates a use of single ‘Three Stage Sewage Treatment System’ made of fiberglass-reinforced plastics. The effluents from the process are chlorinated and stored for discharge. U.S. Pat. No. 6,177,007 to Lee, et al. teaches to install plurality of aerobic and anaerobic tanks, communicating each other to minimize the sludge wash out from anaerobic tank. U.S. Pat. No. 5,843,305 to Kim, et al. teaches to provide a media in a honeycomb type layer arrangement for even distribution of water and sewage, for effective adherence of microorganisms. Microorganisms activating at ambient temperature ranges were selected for commercial applications.
U.S. Pat. No. 4,218,318 to Niimi et al. illustrates a waste water treatment system having a surface layer connected to the bottom conduit (9) by pores between the soil and marvels but does not have separated decanting bath nor oxidation bath. U.S. Pat. No. 4,824,572 to Scott's illustrates a wastewater treatment having a bath consists of bottom concrete (20), small gravel layer (26), larger gravel layer (28), hay or straw layer (32), and high quality top soil (34). The wastewater passes through the voids of the gravel layers. U.S. Pat. No. 4,904,386 to Kickuth is more close to Scott's. Waste water just pass through a bed of soil, gravel and plants. U.S. Pat. No. 4,465,594 to Laak is to utilize filters of stone and sand. Septic tanks separate solid materials. No decanting of solid material is executed after the nitrification step. In U.S. Pat. No. 6,277,274 to Coffman, waste water pass through a plant/soil filter first. Solid materials are screened by the soil mixture (11) and plants (13) contained in the first, water proof, chamber (15). Only liquid pass down to second chamber (39) down under through a vertical pipe line (27). U.S. Pat. No. 5,733,453 to DeBusk is more like Scott's system. U.S. Pat. No. 5,549,817 to Horseley is rather a filtration system than a decomposing organic materials or nitrification system. In U.S. Pat. No. 5,156,741 to Morrison, only liquid dispersing pipes (22) and aeration pipes (20) pass through the bed (10) packed with media (18). In U.S. Pat. No. 5,486,291 to Todd and U.S. Pat. No. 4,415,450 to Wolverton, the wastewater is introduced to the bottom layer, packed with coarse and porous mass barrier of rocks, to discharge to the environment. No special stay in “bath” for neither aeration nor nitrification is installed.
In all of the previous technology, bacteria were artificially embedded into a closed vessels equipped with vent lines. Appearances of those vessels are not environmentally pleasing, as they appear as chemical plants.